ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Explore membership for yourself or for your organization.
Conference Spotlight
2026 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
Latest Magazine Issues
May 2026
Jan 2026
2026
Latest Journal Issues
Nuclear Science and Engineering
June 2026
Nuclear Technology
Fusion Science and Technology
Latest News
NRC proposes changes to its rules on nuclear materials
In response to Executive Order 14300, “Ordering the Reform of the Nuclear Regulatory Commission,” the NRC is proposing sweeping changes to its rules governing the use of nuclear materials that are widely used in industry, medicine, and research. The changes would amend NRC regulations for the licensing of nuclear byproduct material, some source material, and some special nuclear material.
As published in the May 18 Federal Register, the NRC is seeking public comment on this proposed rule and draft interim guidance until July 2.
Thomas E. Stephenson, Alberto M. Ferrer
Nuclear Science and Engineering | Volume 46 | Number 2 | November 1971 | Pages 266-273
Technical Paper | doi.org/10.13182/NSE71-A22360
Articles are hosted by Taylor and Francis Online.
Resonance parameters for 74 resonances of 165Ho below 500 eV, selected from the literature and from values compiled and recommended in BNL-325, are used as the starting point in fitting the total neutron cross-section data to a sum of the Breit-Wigner multilevel scattering and single-level capture formulas. The addition of two bound levels, one for each s-wave spin state, yields a calculated ratio of thermal neutron capture cross sections for the two s-wave spin states which agrees with experiment (≈60% of thermal capture into J = 3 states), as does the calculated value of the thermal capture cross section, 67 b. In addition, the two bound levels enable the fit of the total cross-section data to be extended to very low energies (0.2 mV). The coherent scattering cross section has been calculated and is in good agreement with the experimental value of 9.1 b. The free atom nuclear scattering cross section has been calculated to be 10.6 b. The calculated value of the potential scattering is 7.8 b and the effective scattering radius is 7.9 f. The energy-dependent paramagnetic scattering cross section (23.5 b at 0.0253 eV) and the capture and scattering resonance integrals have also been calculated (≈703 and 125 b, respectively).